People who dismiss their symptoms as trivial or worry about wasting the doctor's time may decide against going to their GP with red-flag cancer warning symptoms, according to a Cancer Research UK study published in the British Journal of General Practice.

Others might decide not to get possible cancer symptoms checked out because they fear a cancer diagnosis, they adopt a stiff upper lip, they lack confidence in the healthcare system, or they think their problem is down to ageing.

Researchers in London and Hull looked at how people who experience possible cancer symptoms decide whether or not to seek medical help. They sent out a health survey that was completed by more than 1,700 people, aged 50 and over, from three London GP practices.

The survey specifically did not mention cancer, but incorporated a list of 17 symptoms including 10 cancer 'alarm' warning signs, such as persistent cough or hoarseness, unexplained lump, persistent change in bowel or bladder habits, and a sore that does not heal.

More than 900 people reported having at least one alarm symptom during the past three months. Researchers carried out in-depth interviews with almost 50 of them, almost half (45 per cent) of whom had not seen their GP about their symptoms.

One woman with persistent abdominal pain did not go for a recommended test. She said: "At times I thought it was bad ... but when it kind of fades away, you know, it does not seem worth pursuing really." A man, who experienced a persistent change in bladder habits, said: "You have just got to get on with it. And if you go to the doctor too much, it is seen as a sign of weakness or that you are not strong enough to manage things on your own."

Dr Katriina Whitaker, a senior research fellow at University College London during the study, said: "Many of the people we interviewed had red flag symptoms but felt that these were trivial and did not need medical attention, particularly if they were painless or intermittent. Others felt that they should not make a fuss or waste valuable NHS resources. The stiff-upper-lip stoicism of some who decided not to go to their doctor was alarming because they put up with often debilitating symptoms. Some people made the decision to get symptoms checked out after seeing a cancer awareness campaign or being encouraged to do so by family or friends - this seemed to almost legitimize their symptoms as important."

Reasons people gave for deciding to seek help included symptoms not going away, instinct that something was not right, and awareness or fear that they might have cancer. A man with an unexplained throat lump said: "But always at the back of your mind you have always got the fear of cancer ........ well it is best to check just in case." However, fear also made some people decide not to check out symptoms, or if symptoms did persist some people began to think they were normal for them.

Some people waited for another reason to visit their GP and mentioned the cancer alarm symptom then. Others said they would rather use an emergency route, such as going straight to A and E, than wait to see a specialist after being referred by their GP.

Dr Richard Roope, Cancer Research UK's GP expert, said: "The advice we give is: if in doubt, check it out - this would not be wasting your GP's time. Often your symptoms won't be caused by cancer, but if they are, the quicker the diagnosis, the better the outcome. Seeking prompt advice from your GP about symptoms, either on the phone or during an appointment, could be a life-saver, whatever your age. And the good news is that more than half of all patients diagnosed with cancer now survive for more than 10 years."

Sara Hiom, director of early diagnosis at Cancer Research UK, said: "Spotting and treating cancer early means patients have a far better chance of beating the disease - so it is important we understand why some people with potential symptoms decide not to get them checked out straightaway. International comparisons have already shown us that the British public are far more worried about being a burden on the health system or 'wasting the doctor's time' than in other developed countries. This study gives us valuable insight into the decision-making process and could help us find ways to encourage everyone with worrying symptoms to seek help as early as possible."